Metabolomic Analysis of Phytochemical Compounds from Ethanolic Extract of Lime (Citrus aurantifolia) Peel and Its Anti-Cancer Effects against Human Hepatocellular Carcinoma Cells

What if the peel you toss in the trash holds a hidden weapon against liver cancer? A new study reveals that lime peel extract—packed with a cocktail of natural compounds—outperforms its pure, isolated ingredients in killing cancer cells.

Lime peels are the unsung heroes of the citrus world—often discarded as waste, yet brimming with bioactive potential. Researchers had already perfected a green extraction method for a hesperidin-limonin-rich peel extract. Now, they've turned their attention to its metabolomic fingerprint and its ability to fight liver cancer cells, specifically the PLC/PRF/5 line.

Using advanced techniques like LC-qTOF/MS and GC-HRMS, the team mapped out the extract's chemical landscape. Beyond the star compounds hesperidin and limonin, they detected 60 additional compounds via LCMS and 22 via GCMS—a complex symphony of phytochemicals. When tested against cancer cells, the extract showed an IC50 of 503.004 µg/mL, while pure hesperidin and limonin had IC50s of 165.615 and 188.073 µg/mL, respectively.

But here's the twist: at their respective IC50 levels, the extract induced significantly more apoptosis (programmed cell death) than either pure compound alone after 24 and 48 hours. A combination of limonin and hesperidin had a synergistic effect, yet still fell short of the extract's potency at 48 hours. The extract also inhibited cancer cell invasion better than limonin, matching hesperidin's performance.

What's remarkable is that the extract contained much lower amounts of hesperidin and limonin than the IC50 doses of the pure compounds—yet it worked better. This suggests the extract's power lies in the synergy of its many components, not just its headline act. The whole, it seems, is greater than the sum of its parts.

Key Points

• Lime peel extract induces more apoptosis than pure compounds
• Extract's synergy outperforms individual phytochemicals
• 60+22 compounds identified beyond hesperidin and limonin